Cotton harvesters typically include a series of harvesting units supported on a harvesting head assembly for harvesting materials from generally parallel rows of cotton plants. The harvesting units are carried by the head assembly in side-by-side relation relative to each other and extend laterally across a forward end of the harvester. To facilitate harvesting of materials from plants arranged in numerous combinations of row spacings, the harvesting units are usually connected to a frame of the head assembly in a manner allowing for lateral adjustment of the harvesting units relative to each other.
Each harvesting unit includes a fore-and-aft extending housing which carries a pair of brush-type rollers for stripping materials from the plants. The materials stripped from the plants are advanced toward and exhausted from a rear end of the harvesting unit housing. A rotatably driven cross-auger on the head assembly gathers and directs the harvested materials exhausted from the harvesting units toward a lateral center of the harvester.
An inherent feature of cotton strippers is that trash is commingled along with the cotton materials during the harvesting process. That is, in addition to the cotton materials, a relatively high amount of trash including green bolls, stones, rocks, plant leaves, twigs, and other plant parts are stripped from the plants by the brush-type rollers of the harvesting units during the harvesting process. As will be appreciated, trash such as leaves, twigs, and other plant parts contaminate and, ultimately, must be separated from the desired cotton materials.
Cleaning systems have been devised to separate the trash from the harvested cotton materials. Field or gin cleaning systems have long been known for use in cleaning the harvested materials of a cotton harvester. Field or gin cleaning systems are arranged separate from the harvester and involve a labor intensive operation which is separate from the harvesting operations.
Other cotton cleaning systems are known to be mounted on the cotton harvester. Those cleaning systems mounted on the cotton harvester have the distinct advantage of cleaning the harvested materials before they are passed to the receptacle or basket.
Known cotton cleaning systems mounted on the harvester typically include a complex assemblage of parts including a plurality of ducts and air systems for handling the harvested materials. A typical cleaning system includes a first duct for upwardly conveying and directing the harvested materials from the cleaning system to the receptacle and a second duct for upwardly delivering the cotton materials from the harvesting head assembly to the cleaning system.
Besides having a plurality of duct structures, these known cleaning systems further include a first air system including a primary fan arranged in combination with the first duct structure for upwardly moving the cotton material from the cleaning system to the receptacle. A second or auxiliary air system, including a second or auxiliary fan arranged in combination with the second duct structure, is required for moving the harvested materials between the head assembly and the cleaning system. As will be appreciated, requiring a secondary air system adds substantially to the number of parts on the harvester and detracts from operation of the harvester by the drawing horsepower to drive the additional fan. Moreover, and for reasons not completely understood, the use of air in advancing harvested materials toward the cleaning system has an adverse effect on the cleaning process and detracts from efficient separation of trash from cotton materials.
Known cleaning systems on the harvester also limit the harvesting capacity of the machine. During the harvesting operation, the auger compiles the harvested material from all the harvester units and the compilation of material is presented to the cleaning system. Accordingly, when operating in heavy harvest conditions, the efficiency of the cleaning system decreases as compared to light harvesting conditions. Moreover, these known cleaning systems are configured to discharge the trash materials therefrom in a concentrated area rather than broadcasting the trash over a larger area.
Thus, there is a need and a desire for a cleaning system which is carried by the cotton harvester and which effectively and efficiently separates trash material from cotton materials with a minimum number of parts.